Human Hormones

Arginine vasopressin, abbreviated as AVP, commonly called vasopressin, is a hormone found in the human body. It is secreted from the posterior pituitary gland. Vasopressin is composed of a linkage of two molecules of the amino acid cysteine and a short side chain. It is classified as a peptide hormone.
Secretion and Production

Vasopressin is secreted by the posterior pituitary gland. It is secreted into the bloodstream as a result of either a reduction in plasma volume or an increase in plasma osmotic pressure. Mainly, it is released when the body is low on water.

Vasopressin has many effects on the human body; however, the most notable is probably its effect on the kidneys. Vasopressin binds to the surface of the kidney tubule, resulting in an increase in the uptake of water into the kidneys. Normal vasopressin secretion allows for more concentrated urine, therefore minimizing a person’s need to urinate. Caffeine inhibits release of vasopressin, therefore increasing the frequency of the need for urination.

Vasopressin release also controls corticotrophin secretion. It promotes vasoconstriction, gluconeogenesis in the liver, and platelet aggregation.
Pharmacological Uses

Synthetic vasopressin is often used therapeutically both to control bleeding in patients with von Willebrand disease and to control bed-wetting in extreme cases. Additionally, vasopressin is often used as a vasopressor to raise the dangerously low blood pressure of septic shock patients in cases where the patient does not respond to treatments of either dopamine or norepinephrine.